#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
    int n = 0;
    int a = 0, b = 0;
    scanf("%d", &n);
    a = (n / 12) * 4;
    b = a + 2;
    printf("%d\n", b);
    return 0;
}